Volume 7

The cyclopædia of practical medicine. Comprising treatises on the nature and treatment of diseases, materia medica and therapeutics, medical jurisprudence, etc. etc / Edited by John Forbes, Alexander Tweedie, John Conolly.

Date:
1833-1835
Catalogue details

Licence: Public Domain Mark

Credit: The cyclopædia of practical medicine. Comprising treatises on the nature and treatment of diseases, materia medica and therapeutics, medical jurisprudence, etc. etc / Edited by John Forbes, Alexander Tweedie, John Conolly. Source: Wellcome Collection.

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    character, and the pruritus with which their manifestation is preceded or accompanied gives but trifling annoyance. While some are sufficiently red, it requires that we pass the fingers over the great majority which stud the surface to distinguish them, so little do they differ from the rest of the skin in colour. The papule remain from a week to a fortnight, and leave the branny desquamation behind on waning; but the duration of the affection in the chronic form is quite indefinite, as fresh suc- cessive cropsof pimples protract it often to many months. It manifests its tenacity sometimes by breaking out in a different part of the body after disappearing from its original situation, and it is liable to recur from the slightest cause, when the patient thinks that he is at length clear of it; such as changes of weather, errors in diet, or unusual exercise. 2. Lichen circumscriptus—tThis variety is distinguished by a marked peculiarity of form. The papule, which in the former species are scattered without order, assume in this a cir- cular arrangement. At the first view nothing may be observed beyond a ring of red papule, but on closer inspection. these are found to enclose areas covered with a minute farinaceous desquamation, which is detached from small papular eminences beneath. ‘The external pa- pule alone manifest any inflammatory red- ness, or if those inside the circles differ from the rest of the skin in colour, it is only by a light pinkish hue. The circumference of these circles, at first-so small that the papule lie clustered in contact, soon spread by new erup- tions, while the old borders fall into the des- quamating centres. They seldom enlarge be- yond the size of a shilling, and when the eruption is extensive, they mingle their circum- ferences, yet not so intimately but that it is always easy to recognize their circular form. This variety occurs as frequently on’ the trunk and face as on the extremities. From its ten- dency to spread and to propagate by forming new patches, it is not to be speedily eradicated. We have observed it occurring most frequently in early youth: it is called by boys at school wildfire. 3. Lichen pilaris.—This differs from the lichen simplex probably in no pathological cha- racter save that the papule are developed at the root of the hairs, which perforate their cen- tres. This variety is remarked to be more chronic in its duration, and to be accompanied with greater irritability of the skin, than any of the preceding. Bateman’s observation accounts for this: he states that it is often connected with derangement of the digestive organs, produced by ardent spirits. 4. Lichen lividus—This is a kind which almost always occurs in persons with constitu- tions broken up by misery and privation. It consists in dark violet pimples scattered here and there on the legs and thighs; they are flat and broad, and are generally mixed with specks, which differ in nothing from purpura, to which disease this form of lichen is evidently allied. It is not so rare -as some authors assert, but it is of little importance in a medical point of view, as in most cases its cure is to be promoted rather by the charity than the pro- fessional services of the physician. 5. Lichen agrius——This is the severest form of this disease, as its name implies.* ‘The pa- pul are smaller than in the lichen simplex ; they occur in congregated masses, and are very numerous. Their colour is deep red, and the skin where they arise is affected with a vivid erythematous inflammation, which spreads be- tween them and beyond them. The heat or pruritus which accompanies their eruption is of the most violent character, and often deprives the patient, night after night, of rest: he cannot avoid scratching the pimples, and often em- ploys a hard brush for this purpose. This proceeding, although rendered irresistible by the intolerable burning and itching, only tends to make matters worse; it aggravates the inflam- mation, and encourages the development of new patches. Besides this, where the papule be- come forcibly abraded, small ulcerations ensue, and a liquid oozes from them which forms thin crusts or scaly concretions. In some rare cases the affection appears to be relieved by the discharge, and having soon thrown off the soft incrustation which the latter formed, the cuta- neous inflammation and its effects subside. The general course of the’ disease is, however, very different; painful exacerbations and new eruptions take place for many weeks; and at length it falls into a chronic condition, in which the inflammation nearly ceases, and the pruritus becomes much mitigated. In this condition it remains for an indefinite period, the serous secretion being checked, and the scaly crusts becoming dry, and diminished to a farinaceous exfoliation. After a severe attack of this affec- tion the skin remains for a long time thickened and rough, and retains a morbid sensibility, which persists for a considerable space. This aggravated form of lichen is sometimes produced from the lichen simplex by causes, general or local, which determine a higher in- flammatory action. In such a case the incon- siderable itching which accompanied the pim- ples of the original species is changed into a burning pruritus; the papule become in some places apparently confluent, and surrounded with a deep red inflammatory areola; and thus it proceeds in the course described. It more generally, however, commences as a distinct form, putting on its characteristic severity from the very beginning. In that state where the lymphy fluid which exudes from the abraded and ulcerated papule concretes into crusts, it approaches very nearly to the character of eczema. If it persist without shewing any tendency to heal, after some time a purulent secretion forms, and may become, as Celsus remarked, really converted into impetigo. The situation of this species is. uncertain. It occurs with about equal frequency on the face, trunk, and extremities. It is not peculiar to any period of life, as it happens at all times * *aypite, ferus, agrestis.